Myiasis of different organs has been reported from various regions in the world. Infection of the eye might appear as eyelids problems or conjunctiva (ophthalmomyiasis externa), or the larvae may invade into the eye (ophthalmomyiasis interna). We report 4 human cases of external ophthalmic myasis from Yazd province, in central region of Iran. All of them referred with symptoms of acute conjunctivitis. Mean age of patients was 34 years. All of them were male and from rural areas. Multiple larvae were observed over the bulbar conjunctiva and cornea. After removing larva, symptoms relieved within a few hours. The organisms were identified as Oestrus ovis